Trigger releasing means for detonation mechanism



April 4, 1961 c. L. PIPER 2,977,381

TRIGGER RELEASING MEANS FOR DETONATION MECHANIISM Filed Feb. 18. 1955 United States Patent TRIGGER RELEASING MEANS FOR DETONA Y TI ON MECHANISM Chester L. Piper, New Haven, Ind., assignor to The Magnavox Company, Fort Wayne, Ind., a corporation Filed Feb. 18, 1955, Ser. No. 489,401 8 Claims. Cl. 102-10.

This invention relates to a means for obtaining release of detonation mechanism adapted for use in the head of a projectile, more particularly in air to air rocket fuzes.

It is the purpose of the invention to provide a safe delay type of releasing or trigger means for effecting the detonation of fuzes, and one which may be sealed against moisture, which will function for detonating air to air rocket heads upon impact with targets from zero angle to angles of high obliquity.

The invention more particularly relates to a detonation mechanism having releasing means comprising a fracturable releasing or initiating pin, which, upon fracture, will I 28. Said stem extends freely into a cavity or chamber permit a spring loaded magnet or stabber to pass into an induction coil connected to an electrical detonator, and wherein the fracture of the releasing pin is occasioned by an impact energy transmitting member which may be in the form of a steel ball directly interposed between the nose of the head and said pin.

Another feature of the invention resides in providing a tension spring bearing against the energy transmitting member or ball by means of which the transmission of energy to the pin sufficient to fracture it may be delayed; and more particularly in providing for a time delay lag in the functioning of the heavy compression spring acting to effect the stabbing action of the pulse producing magnet. Due to the relatively large mass and distance of travel of the magnet and its associated moving parts, the desired time delay between target impact and detonation will be effected.

By means of the structure as hereinafter shown and described, the principle of elastic rebound is used to transfer target impact energy to the energy transmitting member, which member in turn fractures the release mechanism which allows a spring loaded. firing pin to travel a determined distance to actuate a detonator with a determined time delay.

The full nature of the invention will be understood from the accompanying drawing and the following description and claims:

The figure in the drawings shows by way of illustration a central vertical section through a fuze body embodying the invention with the mechanism in position before impact.

In the drawing there is shown a fuze body 10 adapted to be mounted on a projectile, and of a character which may be employed in detonating air to air rocket heads. Said body is tapered, terminating in an impact nose 11 within which there is threaded an axially disposed barrel 12. Within the far end of the barrel from the nose, there is a doughnut type induction coil 13 electrically connected to the detonator (not shown). Such induction coil is secured within the barrel by an end plate 14.

Nested within the body 10 forwardly of the barrel toward the nose 11 there is a spring retaining sleeve 15 provided with a spring pocket 17. Reciprocably mounted 'within the barrel there is a spring bearing collar 18 having press fitted therein a cylindrical magnet 19 adapted to,

generating an electrical pulse within the coil during its Nested with the pocket 17 of the.

pression spring 20, such as to spring load the collar and magnet 19.

Secured axially of the collar 18 by a screw 21 there is a cylindrical initiating pin 22 slideable in the bearing portion 23 of the sleeve 15 having a shoulder in abutment with a shoulder defining areduced bearing portion 24 of said sleeve. The initiating pin 22 is of reduced diameter beyond its shoulder as indicated at 25 to extend through said reduced bearing portion 24, andris provided with an intermediate reduced fracture point indicated at26. Said pin terminates at its free end with a reduced cylindrical fracture portion or stem 27 having a conical end 29 provided adjacent the nose 11 of the fuze body.

Said fracture portion or stem'27 has fixedly secured thereon a retaining flange 30 which bears against the forward face of a retainer washer 31. Said washer is formed with a conical base adapted to freely seat and rock within a conical recess 32 provided in the end face of the sleeve 15 centrally thereof. The angles of the conical surfaces of the washer 31 and recess 32' are so related that the washer may freely rock therein in the plane of the fracture point 26, the washer closely embracing the fracturable portion 25 of the release or initiating pin.

The nose of the fuze body is formed with a laterally displaced off center conical recess 33 in which an impact energy transmitting member, such as a hard steel ball'34 is seated. The position of the ball when seated in the recess is such that it will lie closely adjacent the face of the conical end 28 of the stem, as at the point indicated at 35.

The ball is spring loaded bythe conical spring 36 bear-.

ing'thereon at its smaller end as indicated at the point'37.

The larger end of said spring bears against the end face Thus, at the point 35 the ball is held normally out of pressure contact and in slightly spaced relation to the angularly disposed face of said end 28.

The hard steel ball 34 is operative to accomplish its function in accordance with what may be called the principle of elastic rebound. For example, a piece of hardened steel is known to be almost perfectly elastic in that cornpressive forces acting on such hardened steel deform such steel. After release of compressive forces, the steel regains its exact original form providing that the compressive forces do not exceed those required to deform the steel beyond its limit of elasticity. In accordance with this invention, there is' the hard steel ball 34 maintained in inti-- mate contact with the hard steel nose 11 of'fuze body 10 by means of the conical spring 36. When these two members are forced into compression with each other byforcesi developed at the time of target impact, a natural reaction force causes the surface of conical recess 33 and the co n-' tacting surface of ball 34 to be deformed. Because of the elasticity of the steel in nose 11 and thesteel in ball" 34, these members regain their exact original form afterthe compression forces diminish whereby ball 34 rebounds or springs away from its seat in the nose 11 with s ufli-' cient velocity and energy tofracture pin 22. 'Because of this characteristic of this invention, a missile or projectile embodying this invention can be fired when itcontacts ex-i tremely thin target plates even thoughsuch'plates 'do not' have enough rigidity to permanently deform or crush the. fuze nose Also by utilizingthe principle ofelastic re Patented Apr. 4, 1961 bound, this invention can be actuated by target material which will not actuate a fuze which is initiated by an inertia type of triggerdevice.

k In operation, upon the head of the fuze body striking a target, the impact will cause energy to be transmitted through the ball 34 against the spring 37. There will accordingly be some delayed action determined-by the tension of the spring 37 before impact with the release or initiating pin and the, fracturing thereof.

Following such delayed action, the impact energy is transmitted through the ball to the side of the conical end 28 of the stem 27, forcing it to one side for causing the fracture of the portion 25 of the initiating pin at the fracture point 26. This is permitted through the rocking action of the retaining washer 31', which through the medium of the fixedly secured retaining flange 30, has held the initiating pin 22 in inoperative position against the tension of spring 20.

, When the body of the initiating pin is released by the breaking away of the portion 25 thereof, the spring 20 is free to force it, together with the magnet or stabber 19, down into the opening of the induction coil 13 against the end plate 14. The rapid axial movement of the magnet in its downward travel will generate a pulse within the coil 13 which is transmitted to the detonator. By reason of the relatively larger mass and longer distance of travel of the magnet and its associated moving parts, there will result a further time delay in the detonation of the charge following the fracture and release of the initiating pin. Such delayed action may be determined by where S=distance traveled by pin 22 and where F equalling the force exerted by spring 20 and W equalling the weight of members 18, 19, 20, 21 and 22, exclusive of members 25 and 27.

In another modification of the invention the initiating pin 22 may be provided with a stabbing point in place of magnet 19 whereby initiating pin 22 may be utilized for initiating or firing a primer or detonator.

The invention claimed is:

1. Releasing means for detonation mechanism including a fuze body, a doughnut induction coil therein, a spring loaded initiating pin including a magnet movable into said coil for generating an electrical pulse and a reduced fracturable portion, means for retaining said pin in inoperative position against tension of its load spring, and an impact energy transmitting member carried in the nose of said body positioned to engage one side of said fracturable portion upon target impact to force said portion laterally and effect the fracture thereof at its connection with said initiating pin, to thereby release said pin for causing said magnet to move into said induction coil and thereby generate an actuating pulse to said mechanism.

2. Releasing means for detonation mechanism including a fuze body, a doughnut induction coil therein, a spring loaded initiating pin including a magnet movable into said coil for generating an electrical pulse and a reduced fracturable portion, means for retaining said pin in inoperative position against tension of its load spring, andan impact energy transmitting member carried in thenose of said body positioned to engage the fracturable portion of said pin upon target impact to effect the fracture thereof at its connection with said pin to thereby release said pin for causing said magnet to move into said induction coil and thereby generate an actuating pulse to said mechanism, the. movable assembly of said spring:

loaded firing'pin andmagnet being of such. mass and movable throughsuchdi'stance. as to effect a time delay action between. the fracture of said. pin, and actuation of.the.detonator.

3. Releasing means for detonation mechanism including a fuze body, a spring loaded initiating pin, a fracturable release portion normally integral with said initiating pin, means including said fracturable portion for retaining said pin in inoperative position against tension of its load spring, an impact energy transmitting member car- 1- ried in the nose of said body positioned to engage said nose and one side of said release portion upon target impact to force said release portion laterally and effect the fracture thereof at its connection with said pin, and a spring interposed between said energy transmitting member and said body for holding said member in said engaged position to insure transmission of energy to said release portion.

4. A releasing means for detonation mechanism including a fuze body having a barrel threaded therein,

a doughnut induction coil supported by said barrel, an

engaging said stem having seating engagement with said sleeve for'rocking movement thereon adjacent the point of fracture between said pin and stem for normally rctaining said pin under load with said magnet free of said coil, the free end of said stem being tapered, and an impact transmitting member seated in the nose of said body to one side of said stem for engagement with the conical end thereof adapted to transmit energy to said stem ina direction to fracture it and release said pin.

5. A releasing means for detonation mechanism including a fuze body having a barrel threaded therein, a doughnut induction coil supported by said barrel, an initiating pin, a retaining collar secured to said pin and movable in said barrel, a magnet carried by said collar normally positioned to be moved thereby into said coil for generating a detonating pulse, a spring retaining sleeve slideably supporting said pin, a load spring mounted under compression between said sleeve and collar, a reduced stem extending through said sleeve toward the nose of said body, said stem having a fracturable connection with said pin, a retaining collar surrounding and engaging said stem having seating engagement with said sleeve for rocking movement thereon adjacent the point of fracture between said pin and stem for normally retaining said pin under load with said magnet free of said coil, the free end of said stem being tapered, an impact transmitting member seated in the nose of said body to one side of said stem for engagement with the conical end thereof adapted to transmit energy to said stem in a direction to fracture it and release said pin, and a spring interposed between said energy transmitting member and the end of said sleeve for engaging said member with the nose of said body to insure its energy transmitting movement against said stem.

6. A releasing means for detonation mechanism including a fuze body having a barrel threaded therein, a doughnut induction coil supported by said barrel, an initiating pin, a retaining collar secured to one end of said pin and slideable in said barrel, a cylindrical magnet carried by said collar normally positioned to be moved thereby into said coil for generating a detonating pulse, a spring retaining sleeve slideably supporting said pin, a load spring mounted under compression between said sleeve and collar, a reduced stem extending through said sleeve toward the nose of said body, said stem having a radially and outwardly flared groove providing a reduced fracturable connection with saidpin, a conical retaining collar surrounding; and. engaging: said. stem having seat-= ing engagement in a conical recess provided in the face I of said sleeve for rocking movement thereon adjacent the point of fracture between said pin and stem for normally retaining said pin under load with said magnet free of said coil, the free end of said stem being tapered, and an impact transmitting ball seated in a conical recess formed in the nose of said body to one side of said stem for engagement with the conical end thereof adapted a load spring mounted under compression between said sleeve and collar, a reduced stem extending through said sleeve toward the nose of said body, said stem having a radially and outwardly flared groove providing a reduced fracturable connection with said pin, a conical retaining collar surrounding and engaging said stem having seating engagement in a conical recess provided in the face of said sleeve for rocking movement thereon adjacent the point of fracture between said pin and stem for normally retaining said pin under load with said magnet free of said coil, the free end of said stem being tapered, an impact transmitting ball seated in a conical recess formed in the nose of said body to one side of said stem for engagement with the conical end thereof adapted to transmit energy to said stem in a direction to fracture it and release said pin, and a spring interposed between said energy transmitting ball and the end of said sleeve for engaging said ball with said nose and against said stem.

8. A releasing means for detonation mechanism including a fuze body having a nose portion of relatively hard steel, a spring loaded initiating pin movably mounted within said fuze body and having integral therewith a fracturable portion extending into said nose portion, means including said fracturable portion for retaining said pin in a certain position against tension of its load spring, and an impact energy transmitting member carried in said nose portion of said body engaged with said nose and said fracturable portion at a point out of alignment with the longitudinal axis of said fracturable portion to force said fracturable portion laterally upon target impact and effect the fracture thereof at its connection with said pin, releasing said pin for movement.

References Cited in the file of this patent V UNITED STATES PATENTS 2,508,444 Catlin May 23, 1950 2,703,530 McGee Mar. 8, 1955 FOREIGN PATENTS 6,973 Great Britain 1915 415,610 Great Britain Aug. 30, 1934 

